Process for dyeing textile fibers and preparing high-bulk fabrics



3,414,957 PROCESS FOR DYEING TEXTILE FIBERS AND PREPARING L A T 4 E F mM T K 5 mm m m A ww L n I F Dec. 10, 1968 YARN OF HEAT STABLE F/BRES ANDLOW TEMPERATURE any DYED HEAT .SHR/N/(ABLE INVENTORS,

W/TT LANGSTAFE THOMAS L. SHEALY, JR.

ATTORNEY 8 AGENT United States Patent 3,414,957 PROCESS FOR DYEINGTEXTILE FIBERS AND PREPARING HIGH-BULK FABRICS Witt I. Langstalf andThomas L. Shealy, .Ir., Kingsport,

Tenn., assignors to Eastman Kodak Company, Rochester, N.Y., acorporation of New Jersey Filed June 26, 1964, Ser. No. 378,266

' 16 Claims. (CI. 28-74) This invention relates to dyeing textilefibers, particularly acrylic textile fibers and to the preparation ofhighbulk yarn and fabrics.

In the manufacture of high-bulk knit and woven fabrics such as sweaterfabrics, the common practice is to blend in a yarn two types of fibers,fibers stabilized against heat shrinkage and fibers undergoingsubstantial linear shrinkage upon heating. When yarns containing thesefibers are dyed at the boil as is customary, the fibers differentiallyshrink and a yarn is obtained having characteristic high bulk and loftreadily distinguished from other yarns prepared from non-shrinkablefibers.

The process has several disadvantages residing partly in the fact thatsince dyeing is carried out after the yarn is prepared, the yarns areobtained only in single colors. Yarns containing blends of differentcolors are thus not obtainable. Also, since many types of fiber such aspolyester and acrylic fibers cannot be successfully dyed together andsince the high-shrink fiber cannot be dyed prior to blending, it has notbeen possible to make highbulk blend yarns of this type.

Attempts have been made to use tow dyed material, such as acrylic tow,subsequently to impart the heatshrink property to the dyed fibers.However, the dyed fibers may gradually lose their heat-shrink propertyon natural aging at temperatures common in warehouses and knittingmills. More particularly, the processing of towdyed fiber has beenunsatisfactory in yarn making. The process also has limitations indyeing method.

A common method of dyeing nonbulky yarns is to wind the yarn onperforated tubes and dye the resulting packages by forcing dye liquorthrough them. This operation is less expensive than skein dyeing, inwhich the yarn must be wound onto skeins and tied with strings beforedyeing. It has not been possible to dye high-bulk yarns by, the packagedyeing process since at temperatures normally used, the shrinkable fiberundergoesshrinkage and .the resulting yarn can no longer be bulked.

We have discovered that fibers composed of hydrophobic; syntheticfiber-forming polymers, particularly acrylic and modacrylic polymers,modified so as to be dyeableat low temperatures, can be treated toimpart heat shrinkage properties thereto, for example by drafting andcooling the fibers without relaxing, and the heat-shrinkable fibers canbe dyed alone or combined in a composite yarn with the heat-stablefibers, for example in package form, at a temperature below that causingthe fibers to shrink; thus, dyeing can be carried out at temperaturesbelow 160 F., preferably between 140 F. and 160 F. Subsequent drying ofthe fibers should also be carried out at temperatures below that causingloss of heat shrinkage, for example at about 180 F. to 220 F. The leancomposite yarns thus obtained containing heat-shrinkable and heat-stablefibers are susceptible to heat treatment to produce high-bulk fabrics.As mentioned, it is customary to dye most synthetic fibers, such as theacrylics, at the boil since shrinkage is ordinarily of no consequenceand it was previously not believed possible to satisfactorily dye attemperatures much below boiling.

The staple heat-shrinkable and heat-stable fibers may be combined in thedesired system such as the cotton systern employing the usual picking,carding, drawing, roving and spinning operations. The stapleheat-shrinkable 3,414,957 Patented Dec. 10, 1968 fiber may first be dyedand dried at temperatures below which shrinkage occurs before combiningwith the heatstable fibers into yarn in the cotton system. Otherwise,the yarn containing colorless heat-shrinkable fiber and heatstablefibers can be package or skein dyed before forming into fabric as byknitting or weaving after which the fabric is heated to give high bulk.Similarly, slivers of dyed or undyed heat-shrinkable fibers can beblended with slivers of heat-stable fiber by known methods to producethe heat-shrinkable yarn. While the yarn comprising heatshrinkable andheat-stable fiber is primarily designed for dyeing at low temperatureespecially prior to fabrication, the fabric or garment can be dyed atthe low temperature followed by bulking with heat or dyeing and bulkingof the fabric can be carried out at one time by dyeing at the boil.

It should be noted that the dyeing of the lean yarns from the spinnerscontaining a mixture of colorless heatshrinkable and heat-stable fibers,at the low temperatures required to retain the shrinkage properties, maynot dye the heat-stable fibers since they may be dyeable only at highertemperatures. However, fabrics containing the partially dyed yarn arepleasing in appearance. Accordingly, if desirable, the dyeheat-shrinkable fibers can be combined with heat-stable fibers whichhave been dyed as usual at the boil and the two types of fibers spuninto a lean yarn susceptible to bulking by means of heat. In preparingthe high-bulk yarns, different deniers of the heat-stable andheat-shrinkable fibers can be, e.g., ranging from about 1 to 16 denier.In some cases, it may be desirable to use substantially differentdeniers for e two types of fibers to obtain the desired result.

Representative synthetic hydrophobic fiber-forming polymers susceptibleto such treatment to impart the high heat-shrinkage property thereto andwhich, in the shrinkable form, can be expected to be readily dyeablewithout substantial loss of shrinkage are, for example, acrylonitrilehomopolymers and copolymers including acrylonitrilevinyl halidecopolymers and acrylonitrile-vinylidene halide copolymers, whichfiber-forming polymers have been modified to improve their dyeability byblending or otherwise incorporating into the polymer alkylacrylamidepolymers such as poly-N-alkylacrylamides, acrylic ester polymersincluding polyethylacrylate and polymethylmethacrylate,polyvinylpyridines, poly(vinylpyrrolidones), polyvinyl acetals, e.g.polyvinylbutyral, epoxy resins, e.g. epichlorohydrin-sulfide orepichlorohydrinbisphenol condensates, polyalkylimines, polycarbonates,pollyoxyalkenes, divalent metal salts of aliphatic carboxylic acids,metal sulfonates, etc.

Upon dyeing such heat-shrinkable polymers at relatively low temperaturesat which little shrinkage occurs, when originally containing as much as35 to 45% linear shrinkage, the polymers can be expected! to lose nomore than about 2 to 10% of their heat-shrinkage property, and dyedfibers and yarns are readily obtainable possessing as much as 30 to 40%retained shrinkage. The shrinkage of the fiber before or after dyeing isdetermined by placing a given length in boiling water for two minutesfollowed by quenching with cold water and measuring the change inlength. More accurate results are obtained using samples of tow in thetest prior to cutting it into short staple fiber lengths. Yarn shrinkageis determined similarly except that the measurements of length of yarnbefore and after heating in water is made with a standard amount oftension per denier on the sample of yarn. Accordingly, by heatshrinkablefiber or yarn, we mean the fiber or yarn capable of about 20% or moreshrinkage on heating to elevated temperatures. An especially usefulgroup of polymers, to which substantial heat-shrinkage can be impartedwhich is retained on dyeing at relatively low temperatures, are theacrylonitrile polymers and copolymers preferably containing at leastabout 35% combined acrylonitrile units and up to about 95% acrylonitrileunits, and modified, so as to be dyeable at low temperatures withoutsubstantial loss of shrinkage while retaining good dye fastness, forexample, by 85-5 of vinyl pyridine units as described in U.S. Patents2,990,393 (Re. 25,533) and 3,014,008 (Re. 25,539) or modified by 655% ofvinylpyrrolidone units, for example as described by U.S. Patent2,790,783 or modified with 655% acrylic ester or acrylamide units asdescribed in U.S. Patents 2,879,253, 2,879,254 and 2,838,- 470. Similaramounts of the other polymeric modifiers mentioned above are alsouseful. The polymers will thus retain a useful amount of shrinkage underconditions that lead to significant dyeing of the fibers. A typicalcopolymer composition can be prepared as follows: 93 parts ofacrylonitrile, 7 parts of 2-vinylpyridine, 1500 parts of water, 1.5parts of ammonium persulfate, 1.5 parts of sodium metabisulfite, 10parts of phosphoric acid, and 2.0 parts of sodium lauryl sulfate wereheated at 40 C. for hr. The resultant polymeric slurry, which had anintrinsic viscosity in dimethyl formamide of 1.4, was washed and dried,and after solution in dimethylformamide, was spun under conditions thatgave a fiber having an appreciable degree of residual shrink. Thismaterial could be dyed under conditions that gave a dyed fiber thatstill retained about 70% of its original shrinkage.

A preferred group of copolymers especially adapted to treatment toimpart high heat-shrinkage property to fibers thereof and which arereadily dyeable at low temperatures without appreciable loss of theirshrinkage characteristics, are the modacrylic polymers such as describedin U.S. Patent 2,831,826 composed of a mixture of (A) 70-95% by weightof a copolymer from 30 to 65% by weight of vinylidene chloride or vinylchloride and 7035% by Weight of acrylonitrile, and (B) 305% by weight ofa second polymer from the group consisting of (1) homopolymers ofacrylarnidic monomers of the formula wherein R is selected from thegroup consisting of hydrogen and methyl, and R and R are selected fromthe group :onsisting of hydrogen and alkyl groups of 1-6 carbon atoms,(2) copolymers consisting of at least two of said acrylamidic monomers,and (3) copolymers consisting at at least 50% by weight of at least oneof said acrylimidic monomers and not more than 50% by weight of aJolymerizable monovinyl pyridine monomer.

A particularly efiicacious group of modacrylic polyners for use in thelow temperature dyeing process of the ,nvention is an acetone solublemixture of (A) 7095% W weight of a copolymer of 30-65% by weight ofvinyldene chloride and 70-35% by weight of acrylonitrile and 1B) 305% byweight of an acrylamide homopolymer iaving the above formula wherein R Rand R are as lescribed above. Specific polymers of that group contain095% by weight of (A) a copolymer of from 30-65% y weight of vinylidenechloride and 70-35 by weight of tcrylonitrile and (B) 30-5 by weight ofa lower N -alkyltcrylamide polymer such as poly-N-methylacrylamide,Ioly-N-isopropylacrylamide and poly-N-tertiarybutylacryltmide. It ispolymers such as these which in heat-shrinktble form have the uniqueproperties of dyeing to strong hades at relatively low temperatures suchas below 160 without losing their heat-shrinkage properties.

The colored heat-shrinkable fibers described can then e combined into ayarn together with the heat-stable Inonshrinkable) textile fibers andafter forming into a abric, for example by knitting or weaving, heat canbe tpplied to differentially shrink the fibers to produce a tigh-bulkfabric. The method of applying heat to the abric to shrink the fibers isnot critical, for example, hot it at a temperature not adverselyaffecting the fibers of he order of 250-300 F. can be applied. Theincrease in bulk is readily apparent from counting the increase in thenumber of courses and wales per inch and noting the increase in theweight of fabric per square yard. The improved fullness of hand willalso be apparent. In this process, the combination of the specifiedshrinkable fibers and low temperature dyeing produces fibers whoseheatshrink properties are maintained on natural aging under roomconditions over an extended period of time.

The heat-stable fibers which are used in the high-bulk fabrics togetherwith the shrinkable fibers (i.e. modacrylic fibers of U.S. Patent2,831,826 having the above formula) include a wide variety of fiberssuch as cotton, mohair, wool, viscose, heat-stable acrylonitrilehomopolymers and copolymers such as those sold under the names Creslan,Acrilan, Dynel, Zefran, Orlon, the linear terephthalate polyesters suchas the linear cyclohexane-1,4-dimethanol terephthalate polyestersdescribed in the Kibler et al. U.S. Patent 2,901,466, granted Aug. 25,1959, which have been heat stabilized as described in the patent. Theheat-stabilized glycol terephthalate polyesters, including polyethyleneterephthalate, described in the Whinfield et al. U.S. Patent 2,465,319,granted Mar. 22, 1949, are also very useful as the heat-stable componentof the high-pile fabric.

The dyes are particularly useful for dyeing the heatshrinkable fibers,particularly the mod-acrylic fibers described above include the cationicor basic dyes well known in the art for dyeing acrylic fibers, forexample the Basacryl series of cationic dyes which are usually used fordyeing acrylonitrile polymers such as Acrilan and Dynel at the boil, forexample: Basacryl Yellow 5RL (Cl. Basic Yellow 25), Basacryl Red 'GL(C.I. Basic Red 29), Basacryl Blue 3RL (01. Basic Blue 53) and BasacrylBlue GL (C.I. Basic Blue 54). The Sevron series of dyes also representcationic dyes useful in the process and include, for example, thecationic cyanine, methine, anthraquinone, oxazine and triphenylmethanedyes such as Sevron Yellow L (0.1. Basic Yellow 13), Sevron Yellow R(0.1. Basic Yellow 11), Sevron Orange G (C.I. Basic Orange 21), SevronBlue B (C.I. Basic Blue 21), Sevron Blue 2G (C.I. Basic Blue 22), SevronBlue 5G (C.I. Basic Blue 4), Sevron Brilliant Red 4G (0.1. Basic Red 14)and Sevron Green B (C.I. Basic Green 3).

The following are representative of the useful disperse dyes: 4 (2methanesulfonyl 4' nitrophenylazo)-N- ,3 cyanoethyl N ,9acetoxyethylaniline; 4 (6 methanesulfonyl 2 benzothiazolylazo) N Bcyanoethyl- B hydroxyethylaniline; 2 nitro 4 \I,N dimethylsulfonamido 4'ethoxydiphenylamine; and 2 nitro 4 sulfonanilidodiphenylamine.Representative of the useful premetallized dyes are: Cibalan Yellow2BRL, C.I. Acid Orange 87; Cibalan Red 2GL, C.I. Acid Red 211; CibalanOrange RL, C.I. Acid Orange 88; Cibalan Blue BL, C.I. Acid Blue 168;Cibalan Brown ZGL, no CI. number; and Cibalan Grey 2GL, C.I. Acid Black62.

The usual stock or package dyeing methods can be used for dyeing theheat-shrinkable fibers. Dyeing assistants and leveling agents such asnonionic surfactants and phosphate compounds are useful as shown in thefollowing examples.

Methods known in the art can be used for imparting the heat-shrinkproperties to the fibers such as the modacrylic fibers of U.S. Patent2,831,826 described above. These methods include spinning the modacrylicfibers from solvent, passing the tow bundle over heated rolls anddrafting the fibers to about 3-6 times their original length at atemperature of about 250-400 F. followed by cooling the fibers withoutrelaxing or further heat treatment. A particularly useful method forimparting heat-shrinkage to the modacrylic fibers of the above patentinclude drafting the fibers at a temperature of the order of 250300 F.and spraying the fibers with chilled water or passing them over a coolroll without relaxing or further heat treatment. When fibers such as theabove modacrylic fibers are to be utilized as the heat-stable componentof the high-bulk fabric, they are drafted with heat and relaxed andheat-stabilized in accordance with the usual practice.

The accompanying drawings illustrate diagrammatically in Stage 1 theappearance of a representative corn= posite yarn composed ofheat-shrinkable fibers and heatstable fibers, as obtained in a processsuch as the cotton process, the heat-shrinkable fibers having been dyed,before or after combining into the yarn, at a temperature below thatcausing heat-shrinkage. In Stage 2 the same yarn is showndiagrammatically substantially as it would appear after heating to causedifferential shrinkage of the fibers and thus bulking of the yarn.

The following examples will serve to illustrate our invention.

EXAMPLE I A modacrylic fiber was prepared as described in US. Patent2,831,826 comprising a mixture of a icopolymer of vinylidene chlorideand acrylonitrile and a minor amount of a poly(lower N-alkylacrylamide),the fiber being drafted with heat and cooled without relaxing to imparthigh heat-shrinkage thereto, after which the tow was cut to staplelength. Fifty pounds of this 3 d./f., l /f'length bright luster highshrinkage modacrylic staple fiber was dyed a medium brown shade in aRiggs and Lombard stock dyeing machine. The machine was filled tothree-quarters capacity with water at 80 F. The fiber was loaded intothe water by hand and distributed evenly. The machine was filled to thecorrect volume with water and circulation of the water was begun. Thefollowing chemicals were added to the machine and circulated forminutes.

Percent Acetic acid (56%) 1.0 Sodium acetate 0.5 Fatty ester sulphate1.0 Self-emulsifying organic phosphate 1.5

Percentages based on fiber weight.

The following dyes based on the fiber weight were pasted with aceticacid and dissolved in water, then added to the dye machine andcirculated for 10 minutes.

Percent Basacryl Blue'GL 0.36 Basacryl Red GL 0.52 Basacryl Yellow SRL1.66

The dye bath temperature was raised from 80 F. to 140 F. over a periodof 45 minutes. The fiber was dyed 60 minutes at 140 F. then rinsed at120 F., removed from the machine and the water extracted in centrifuge.The fiber was then dried at 190 F.

Forty pounds of the dyed staple fiber was blended at the cotton pickerwith 60 pounds of a cyclohexane-l,4- dimethanol terephthalate polyesterheat stable fiber of 4.5 d./ f., bright luster, 1%"cut. 'Usingconventional cotton spinning procedures, a 14/1 yarn with 9.8 t.p.i. Zsingles was spun. This was two-plied with 4.28 twist and cone'd.

I This yarn was knit into a fabric on a Dubied NHF-S V-bed knitter. Itwas knit from two cones of yarn. The greige'fabrie contained 6.5courses/inch and 6 wales/ inch and weighed about 7 ounces per squareyard.

The grei ge fabric was then placed in a boiling water bath for 20minutes. It was removed and tumble dried at 220 F. The fabric showed aremarkable degree of bulking as evidenced by the change in constructionto values of 10 courses/inch and 9 wales per inch and an increasedweight to about 10 ounces per square yard. The fullness of hand of thefinished fabric was remarkably improved as compared to the greigeas-knit fabric. The finished fabric also had much improved cover. Theseimprovements .are attributed to the retained shrinkage ability of thestock dyed fiber, which caused the fibers to Untreated Treated GreigeBoiled Soeeific Volume, Cu. In./Lb 64 106 Yarn Count, Cotton System 13.8/2 10. 2/2

The bulking potential of the yarn is not lost with age. This is shown bytesting the contraction or shrinkage in length of the yarn over a periodof time, illustrated by the following data obtained for a yarn similarto that used in the above example.

Shrinkage in boiling water, percent Freshly spun 24.6 Aged 11 days 28.2Aged 3 months 29.0 Aged 3 months 24.2 Aged 4 months 29.2 Aged 4% months26.0

Thus the dyed shrinkable fiber or a yarn or fabric containing it can beshipped or stored for significant periods of time before it is bulkedwithout loss of bulking potential. This is of considerably advantage asoften the fiber is dyed in one plant, spun into yarn in a second plant,knit into fabric in a third plant and made into a garment in a fourthplant and the final finishing of the garment may thus take place sometime after the shrinking fiber is dyed.

While in this example, the heat-stable polyester fiber was not dyed, itcan be stock dyed to any desired shade for cross dye or heather effects.Or, if desired, two or more yarns can be made from different coloredstock dyed or natural staple fibers and used in knitting to producebulky knit garments having stripe and other pattern color effects asdesired.

Thus, it has been found that the shrink-ability of the fibers is notchanged by the dyeing process. Accordingly, a natural yarn and a coloredyarn can be knit together into a fabric and bulked to produce a colorand whitestriped or patterned sweater or dress at low cost.

EXAMPLE II Example I was repeated using a heat-stable polyethyleneterepthalate polyester fiber as the nonshrinking component in a blendwith the shrinkable modacrylic fiber. A similar improvement in the bulk,hand and cover of the finished fabric was noted.

EXAMPLE llII Example I was repeated using a heat-stable unmodifiedacrylonitrile polymer staple fiber as the non-shrinking fiber componentof the blend. When the knit fabric was finished, the same improvement inbulk found in Example I was noted.

EXAMPLE IV A blend yarn was spun from 40% of the 3 d./f., 2 /2shrinkable modacrylic staple fiber and 60% of acyclohexane-1,4-dimethanol terephthalate polyester staple fiber of 4.5d./f. and 2 /2 length. Both fibers were bright luster. The yarn was spunon the cotton system into a 20/2 cotton count size yarn.

The yarn was package dyed according to the following procedure:

(1) Wind medium soft packages.

(2) Set machine on five minutcsin and five minutes out.

(3) Add dyeing assistants over two cycles at 80 F. and

run one cycle.

(4) Add basic dyes over two cycles on outsidein portion at 80 F.

() Raise temperature at 140 F. in 45 minutes.

(6) Run one hour at 140 F.

(7) Rinse, scour, rinse and dry at 190 F.

Untreated Treated Specific Volume, Cu. In./Lb 59 95 Cotton Count, YarnSize 8 The shrinkage of this dyed yarn was 31% when exposed to boilingwater immediately after dyeing. Three months after dyeing a secondsample of the yarn was bulked in boiling water and was found to have 32%shrinkage.

The ability of the yarn of the invention represented by this example, tobe bulked after package dyeing is unique. In the prior art, it has notbeen possible to produce a yarn from a blend of heat-stable andheat-shrinkable fibers of yarns, package dye the yarn and subsequentlybulk the yarn in a fabric made from the yarn by shrinking the shrinkablefiber component of the yarn.

EXAMPLE V Example IV was repeated except that the yarn was skein dyedaccording to the following procedure:

(1) Wet out.

(2) Use a cycle of 6 minutes forward and 4 minutes reverse How onHussong machine.

(3) Add dyeing assistants at 80 F. and run one cycle.

(4) Add one half of basic dye at 80 F. and run one cycle. Rotate skeins.

(5 Add remaining one half of basic dye at 80 F. and

run one cycle. Rotate skeins.

(6) Raise temperature to 100 F. in one cycle. Rotate skeins.

(7) Raise temperature to 120 F. in one cycle. Rotate skeins.

(8) Raise temperature to 140 F. in one cycle. Rotate skeins.

(9) Raise temperature to 160 F. in one cycle. Rotate skeins.

(10) Run for one hour at 160 F. Rotate skeins every two cycles.

(11) Rinse, scour, rinse, soften, extract, dry at 190 F.

The skein dyed yarn was knit into fabric and bulked with good results asin Example IV.

EXAMPLE VI Example IV was repeated except that polyethylene ter-:phthalate heat-stable fiber was substituted for the heat- ;tablepolyester yarn of Example IV. The yarn was packtge dyed, knit, andbulked by steaming. A similar improvement in the bulk of the finishedfabric was noted.

EXAMPLE VII Example IV was repeated except that an unmodifiedacylonitrile polymer fiber was used as the heat-stable com- )onent ofthe blend. The knit fabric made from the package dyed yarn was steamtreated to shrink the modacrylic component and a remarkable improvementin bulk was noted.

EXAMPLE VIII Example IV was repeated except that an apparel grade woolfiber was substituted for the heat-stable polyester fiber. Similarresults were obtained as in Example IV.

EXAMPLE IX Example IV was also repeated using cotton fiber in place ofthe heat-stable polyester fiber. Similar results were obtained as inExample IV.

While the invention is demonstrated in the examples with knit fabrics,equally impressive results can be obtained in woven fabrics. Forexample, the package dyed unbulked yarn can be woven into a loose weavefabric. The fabric is then treated with steam or boiling in a relaxedstate so that the dyed shrinking component can cause contraction and aresultant bulking of the fabric to give it improved fullness of hand,thickness, heat insulation ability and bulk. Or, if desired, the fabriccan be woven from alternate multiple picks and Warp ends of apotentially shrinkable dyed yarn and a non-shrinkable dyed yarn. Whensuch a fabric is then steamed or treated in hot water, a popcorn orwafiie texture woven fabric is obtained.

It should be pointed that there is a particular advantage in usingcycl0hexane-1,4-dimethanol terephthalate heat-stable fiber in foregoingblends because of its low shrinkage in boiling water of 0.5% and low hotair oven shrinkage of 4% at 220 C. By contrast, heat-stable polyethyleneterephthalate polyester has 2.8% shrinkage in boiling Water and 11.2%shrinkage in 190 C. hot air and some heat-stable acrylic fibers may have3% or more shrinkage in boiling water and up to 20% shrinkage in 190 C.hot air. Since the bulking of a yarn composed of shrinking andnon-shrinking fibers is based on the difference in potential shrinkageat a given temperature, it can be seen that with the same shrinkablefiber, the cyclohexane-1,4-dimethanol terephthalate polyester fiber willmake it possible to achieve higher bulk levels than other lessheat-stable fibers which have higher shrinkage values in hot water orair.

EXAMPLE X A staple yarn was spun from a blend of 40% of shrinkablemodacrylic fiber such as used in Example I, 3 d./f., 2 /2 cut, brightluster fiber and 60% of a cyclohexane- 1,4-dimethanol terephthalatepolyester staple fiber of 4.5 d./f. and 2% cut of bright luster. Theyarn was of a 14/ 2 ply cotton count construction.

The yarn was knit into a fabric containing 6.5 courses/ inch and 6wales/inch. The greige fabric was then dyed and bulked by the followingprocedure.

(1) Bag fabrics or garments.

(2) Wet out at F.

(3) Add assistants and circulate for 10 minutes at 80 F.

(4) Add basic dyes and circulate for 10 minutes at 80 F.

(5) Raise temperature to 160 F. in 45 minutes. Run one hour at 160 F.

(6) Rinse, scour, rinse.

(7) Bulk-Add 50% common salt and boil for 20 minutes. Cool slowly to F.Rinse, soften, extract and dry.

The dyed and bulked fabric exhibited good bulk, fullness of hand andcover. It contained 12 courses/inch and 9 wales/ in ch.

EXAMPLE XI Example X was repeated using in one case heat-stableacrylonitrile polymer fiber and in one case a heat-stable polyethyleneterephthalate fiber in place of the heat-stable polyester of Example X.Similar bulking results were obtained.

EXAMPLE XII A blend of 50% 3 d./f., 2 /2 bright shrinkable modacrylicfiber of Example I and 50% of the same fiber but nonshrinkable 16 d./f.,2 /2 bright fiber was spun into an 8/1 yarn and knit on a Tompkinscircular knit machine into a fiat knit fabricof about 28 ounces persquare yard. Using low temperature dyeing techniques, the fabric wasdyed according to .the following procedure:

Dyeing procedure The fabric was dyed in ropeform at 140 F. for one hourusing the formula listed below to make a beige shade:

Percent Basacryl Blue GL, C.I. Basic Blue 54 (supplement) 0.027 BasacrylRed GL, Cal. Basic Red 29 (supplement) 33 Basacryl Yellow 5 RL, C.I.Basic Yellow 25 (supplement) 0.13 Direct Brown, (LI. 95 0.10Superlitefast Blue 8 GLN 0.0064 Acetic acid (56%) 1.0 Sodium acetate 0.5Sodium chloride 40.0 Fatty ester sulfate 1.0 Self-emulsifying organicphosphate 1.5

After dyeing, the fabric was rinsed and after treated with a cationicsoftener for 20 minutes at 120 F. To remove excess water, the fabric wasvacuum extracted and dried at 190 F. The fabric was then passed throughthe normal pile fabric finishing operation of napping, shearing andheating at 280 to 300 F. to shrink the shrinkable fiber and provide a2-pile height effect. The pile of the fabric was then heat-polished andan imitation fur fabric resulted.

The invention has been described in considerable detail with particularreference to certain preferred embodiments thereof, but it will beunderstood that variations and modifications can be effected within thespirit and scope of the invention as described hereinabove, and asdefined in the appended claims.

What we claim is:

1. The process of preparing an article having highbulk characteristicscomprising blending heat-stable fibers and heat-shrinkablemodacrylicfibers, forming the blend of fibers into a yarn, dyeing saidyarn at a temperature below 160 F., drying the yarn at a temperaturebelow 190 F. imparting any significant; shrinkage thereto, forming thearticle from said yarn, and subsequently heating said article at atemperature above 200 F. to thereby shrink said heat-shrinkable fibersand bulk the formed article.

2. The process of preparing an article having highbulk characteristicscomprising dyeing a first quantity of heat-shrinkable modacrylic fibersat a temperature below 160 F., drying said fibers at a temperature below190 F. without impairing the shrink characteristics thereof, dyeing anddrying a second quantity of heat-stable fibers, blending said fiber andforming the blended fibers into a yarn, forming an article from theyarn, and subsequently heating said article at a temperature above 200F. to thereby shrink said heat-shrinkable fibers and bulk the formedarticle.

3. The process of preparing an article having highbulk characteristicscomprising dyeing a first quantity of heat-shrinkable modacrylic fibersat a temperature below 160 F., drying said fibers at a temperature below190 F. without impairing the shrink characteristics thereof, blendingsaid fibers with a second quantity of heat-stable fibers and forming ayarn therefrom, forming an article from the yarn, and subsequentlyheating said article at a temperature above 200 F. to thereby shrink thesaid heat-shrinkable fibers and bulk the formed article.

4. The process of preparing an article having highbulk characteristicscomprising blending heat-stable fibers and heat-shrinkable modacrylicfibers and forming a yarn therefrom, forming said yarn into an article,dyeing the article at a temperature below F., drying said article at atemperature below F., without impairing the shrinkage characteristicsthereof, and subsequently heating the dyed article at a temperatureabove 200 F. to thereby shrink said heat-shrinkable fibers and bulk theformed article.

5. The process of claim 1 wherein the heat-shrinkable fibers impartedheat-shrinkage include an acrylonitrile polymer.

6. The process of claim ,1 wherein the heat-shrinkable fibers impartedheat-shrinkage include a mixture of (A) 70-95% by weight of a copolymerof from 30 to 65% by weight of a member of; the class consisting ofvinyl chloride and vinylidene chloride and 70 to 35% by weight ofacrylonitrile, and (B) 30-5% by weight of a second polymer from thegroup consisting of (1) homopolymers of acrylamidic monomers of theformula wherein R is selected from the group consisting of hydrogen andmethyl, and Rgand R are selected from the group consisting of hydrogenand alkyl groups of 1-6 carbon atoms, (2) copolymers consisting of atleast two of said acrylamidic monomers, and (3) copolymers consisting ofat least 50% byweight of at least one of said acrylamidic monomers andnot more than 50% by weight of a polymerizable monovinyl pyridinemonomer, dyed at a temperature below that causing the fibers to shrink.

7. The process of claim 6 wherein the heat-stable fibers include alinear terephthalate polyester.

8. The process of claim 6 wherein the heat-stable fibers include alinear 1,4-cyclohexanedimethanol polyester.

9. The process of claim 6 wherein the heat-stable fibers include alinear glycol terephthalate polyester.

10. The process of claim 1 wherein the heat-shrinkable fibers impartedheat-shrinkage include an acetone soluble mixture of (A) 70-95% of acopolymer of 30-65% by weight of vinylidene chloride and 70-85% byweight of acrylonitrile, and (B) 305% of poly-N-isopropylacrylamide dyedat a temperature below that causing the fibers to shrink.

11. The process of claim 2 wherein the heat-shrinkable fibers include anacrylonitrile polymer.

12. The process of claim 2 wherein the heat-shrinkable fibers include amixture of (A) 70-95% by weight of a copolymer of from 30 to 65% byweight of a member of the class consisting of vinyl chloride andvinylidene chloride and 70 to 35 by weight of acrylonitrile, and (B)305% by weight of; a second polymer from the group consisting of (1)homopolymers of acrylamidic monomers of the formula O R: (3H =o-o-N B R3wherein R is selected from the group consisting of by drogen and methyl,and R and R are selected from the group consisting of hydrogen and alkylgroups of 1-6 carbon atoms, (2) copolymers consisting of at least two ofsaid acrylamidic monomers, and (3) copolymers con sisting of at least50% by weight of at least one of said acrylamidic monomers and not morethan 50% by weight of a polymerizable monovinyl pyridine monomer, dyedat a temperature below that causing fibers to shrink.

13. The process of claim 12 wherein the heat-stable fibers include alinear terephthalate polymer.

14. The process of claim 12 wherein the heat-stable fibers include alinear 1,4-cyclohexanedimethanol terephthalate polyester.

r t 1 1 12 15. The process of claim 12 wherein the heat-stable 2,991,5387/1961 Hendley 28-75 fibers include a linear glycol terephthalatepolyester. 3,046,724 7/ 1962 Ward 57140 16. The process of claim 2wherein the heat-shrinkable 3,177,644 4/1965 Aspy et al. 57-140 fibersinclude an acetone soluble mixture of (A) 7095% 3,199,281 8/ 1965 Maerovet al 57140 of a copolyrner of 30-65% by weight of vinylidene chlorideand 70-35% by weight of acrylonitrile, and (B) FOREIGN PATENTS 305% ofpoly-N-isopropylacrylarnide, dyed at a tem- 1,363,235 6/ 1964Fral'lceperature below that causing the fibers to shrink. 644,304 10/1950 Great Brltaln.

References Cit d 10 JOHN PETRAKES, Primary Examiner. UNITED STATESPATENTS Us CL XIR 2,810,281 10/1957 Appleton et al. 66202 2,831,8264/1958 Coover,etal. 26032.8 28"75;57 153 164

1. THE PROCESS OF PREPARING AN ARTICLE HAVING HIGHBULK CHARACTERISTICSCOMPRISING BLENDING HEAT-STABLE FIBERS AND HEAT-SHRINKABLE MODACRYLICFIBERS, FORMING THE BLEND OF FIBERS INTO A YARN, DYEING SAID YARN AT ATEMPERATURE BELOW 160*F., DRYING THE YARN AT A TEMPERATURE BELOW 190*F.IMPARTING ANY SIGNIFICANT SHRINKAGE THERETO, FORMING THE ARTICLE FROMSAID YARN, AND SUBSEQUENTLY HEATING SAID ARTICLE AT A TEMPERATURE ABOVE200*F. TO THEREBY SHRINK SAID HEAT-SHRINKABLE FIBERS AND BULK THE FORMEDARTICLE.